Another cheap Radar Motion detection module
Some chat on these Pete Scargill's site:http://tech.scargill.net/microwave-for-the-weekend/
It uses a different chip (RCWL-0516) to the other cheap radar modules discussed here last year...
Ive ordered two to play with so will report back in a few months if they work for me.
I wonder how much power it uses, because I suspect it will not be very battery friendly
Some more info here:
...but not any power consumption figures....
3 mA is not very friendly